This project proposes to evaluate the educational efficacy and psychological impact of screening and genetic counseling for beta-thalassemia trait in a health maintenance organization. The specific aims are: 1. To evaluate effects of characteristic of the counselee and of the counseling method on: (a) comprehension (information retained, misinformation acquired, ability to reason with concepts and attitudes acquired), (b) psychologic impact (affective response, coping, self-image), and (c) changes in behavior (reproductive, marital, sexual, health-related). 2. To determine which features of the counselee or counseling strategy predispose to optimal results in 1a, 1b, or 1c. 3. To provide an empirical basis for cost-benefit analysis with regard to counseling method in mass screening.